/* The MIT License

   Copyright (c) 2008, by Attractive Chaos <attractivechaos@aol.co.uk>

   Permission is hereby granted, free of charge, to any person obtaining
   a copy of this software and associated documentation files (the
   "Software"), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to
   permit persons to whom the Software is furnished to do so, subject to
   the following conditions:

   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   SOFTWARE.
*/

/*
  An example:

#include "khash.h"
KHASH_MAP_INIT_INT(32, char)
int main() {
    int ret, is_missing;
    khiter_t k;
    khash_t(32) *h = kh_init(32);
    k = kh_put(32, h, 5, &ret);
    if (!ret) kh_del(32, h, k);
    kh_value(h, k) = 10;
    k = kh_get(32, h, 10);
    is_missing = (k == kh_end(h));
    k = kh_get(32, h, 5);
    kh_del(32, h, k);
    for (k = kh_begin(h); k != kh_end(h); ++k)
        if (kh_exist(h, k)) kh_value(h, k) = 1;
    kh_destroy(32, h);
    return 0;
}
*/

/*
  2008-09-19 (0.2.3):

    * Corrected the example
    * Improved interfaces

  2008-09-11 (0.2.2):

    * Improved speed a little in kh_put()

  2008-09-10 (0.2.1):

    * Added kh_clear()
    * Fixed a compiling error

  2008-09-02 (0.2.0):

    * Changed to token concatenation which increases flexibility.

  2008-08-31 (0.1.2):

    * Fixed a bug in kh_get(), which has not been tested previously.

  2008-08-31 (0.1.1):

    * Added destructor
*/


#ifndef __AC_KHASH_H
#define __AC_KHASH_H

#define AC_VERSION_KHASH_H "0.2.2"

#include <stdint.h>
#include <stdlib.h>
#include <string.h>

typedef uint32_t khint_t;
typedef khint_t khiter_t;

#define __ac_HASH_PRIME_SIZE 32
static const uint32_t __ac_prime_list[__ac_HASH_PRIME_SIZE] =
{
  0ul,          3ul,          11ul,         23ul,         53ul,
  97ul,         193ul,        389ul,        769ul,        1543ul,
  3079ul,       6151ul,       12289ul,      24593ul,      49157ul,
  98317ul,      196613ul,     393241ul,     786433ul,     1572869ul,
  3145739ul,    6291469ul,    12582917ul,   25165843ul,   50331653ul,
  100663319ul,  201326611ul,  402653189ul,  805306457ul,  1610612741ul,
  3221225473ul, 4294967291ul
};
//这些宏是什么意思,可能是hash表的一个操作
#define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2)
#define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1)
#define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3)
#define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1)))
#define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1)))
#define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1)))
#define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1))

static const double __ac_HASH_UPPER = 0.77;
//第二个和第三个都是类型
//这个宏下定义了所有函数
#define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
    typedef struct {                                                    \
        khint_t n_buckets, size, n_occupied, upper_bound;               \
        uint32_t *flags;                                                \
        khkey_t *keys;                                                  \
        khval_t *vals;                                                  \
    } kh_##name##_t;                                                    \
    static inline kh_##name##_t *kh_init_##name() {                     \
        return (kh_##name##_t*)calloc(1, sizeof(kh_##name##_t));        \
    }                                                                   \
    static inline void kh_destroy_##name(kh_##name##_t *h)              \
    {                                                                   \
        if (h) {                                                        \
            free(h->keys); free(h->flags);                              \
            free(h->vals);                                              \
            free(h);                                                    \
        }                                                               \
    }                                                                   \
    static inline void kh_clear_##name(kh_##name##_t *h)                \
    {                                                                   \
        if (h && h->flags) { \
            memset(h->flags, 0xaa, ((h->n_buckets>>4) + 1) * sizeof(uint32_t)); \
            h->size = h->n_occupied = 0;                                \
        }                                                               \
    }                                                                   \
    static inline khint_t kh_get_##name(kh_##name##_t *h, khkey_t key)  \
    {                                                                   \
        if (h->n_buckets) {                                             \
            khint_t inc, k, i, last;                                    \
            k = __hash_func(key); i = k % h->n_buckets;                 \
            inc = 1 + k % (h->n_buckets - 1); last = i;                 \
            while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
                if (i + inc >= h->n_buckets) i = i + inc - h->n_buckets; \
                else i += inc;                                   	    \
                if (i == last) return h->n_buckets;                     \
            }                                                           \
            return __ac_iseither(h->flags, i)? h->n_buckets : i;            \
        } else return 0;                                                \
    }                                                                   \
    static inline void kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
    {                                                                   \
        uint32_t *new_flags = 0;                                        \
        khint_t j = 1;                                                  \
        {                                                               \
            khint_t t = __ac_HASH_PRIME_SIZE - 1;                       \
            while (__ac_prime_list[t] > new_n_buckets) --t;             \
            new_n_buckets = __ac_prime_list[t+1];                       \
            if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0; \
            else {                                                      \
                new_flags = (uint32_t*)malloc(((new_n_buckets>>4) + 1) * sizeof(uint32_t)); \
                memset(new_flags, 0xaa, ((new_n_buckets>>4) + 1) * sizeof(uint32_t)); \
                if (h->n_buckets < new_n_buckets) {                     \
                    h->keys = (khkey_t*)realloc(h->keys, new_n_buckets * sizeof(khkey_t)); \
                    if (kh_is_map)                                      \
                        h->vals = (khval_t*)realloc(h->vals, new_n_buckets * sizeof(khval_t)); \
                }                                                       \
            }                                                           \
        }                                                               \
        if (j) {                                                        \
            for (j = 0; j != h->n_buckets; ++j) {                       \
                if (__ac_iseither(h->flags, j) == 0) {                  \
                    khkey_t key = h->keys[j];                           \
                    khval_t val;                                        \
                    if (kh_is_map) val = h->vals[j];                    \
                    __ac_set_isdel_true(h->flags, j);                   \
                    while (1) {                                         \
                        khint_t inc, k, i;                              \
                        k = __hash_func(key);                           \
                        i = k % new_n_buckets;                          \
                        inc = 1 + k % (new_n_buckets - 1);              \
                        while (!__ac_isempty(new_flags, i)) {           \
                            if (i + inc >= new_n_buckets) i = i + inc - new_n_buckets; \
                            else i += inc;                              \
                        }                                               \
                        __ac_set_isempty_false(new_flags, i);           \
                        if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { \
                            { khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
                            if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \
                            __ac_set_isdel_true(h->flags, i);           \
                        } else {                                        \
                            h->keys[i] = key;                           \
                            if (kh_is_map) h->vals[i] = val;            \
                            break;                                      \
                        }                                               \
                    }                                                   \
                }                                                       \
            }                                                           \
            if (h->n_buckets > new_n_buckets) {                         \
                h->keys = (khkey_t*)realloc(h->keys, new_n_buckets * sizeof(khkey_t)); \
                if (kh_is_map)                                          \
                    h->vals = (khval_t*)realloc(h->vals, new_n_buckets * sizeof(khval_t)); \
            }                                                           \
            free(h->flags);                                             \
            h->flags = new_flags;                                       \
            h->n_buckets = new_n_buckets;                               \
            h->n_occupied = h->size;                                    \
            h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
        }                                                               \
    }                                                                   \
    static inline khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
    {                                                                   \
        khint_t x;                                                      \
        if (h->n_occupied >= h->upper_bound) {                          \
            if (h->n_buckets > (h->size<<1)) kh_resize_##name(h, h->n_buckets - 1); \
            else kh_resize_##name(h, h->n_buckets + 1);                 \
        }                                                               \
        {                                                               \
            khint_t inc, k, i, site, last;                              \
            x = site = h->n_buckets; k = __hash_func(key); i = k % h->n_buckets; \
            if (__ac_isempty(h->flags, i)) x = i;                       \
            else {                                                      \
                inc = 1 + k % (h->n_buckets - 1); last = i;             \
                while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
                    if (__ac_isdel(h->flags, i)) site = i;              \
                    if (i + inc >= h->n_buckets) i = i + inc - h->n_buckets; \
                    else i += inc;                                      \
                    if (i == last) { x = site; break; }                 \
                }                                                       \
                if (x == h->n_buckets) {                                \
                    if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
                    else x = i;                                         \
                }                                                       \
            }                                                           \
        }                                                               \
        if (__ac_isempty(h->flags, x)) {                                \
            h->keys[x] = key;                                           \
            __ac_set_isboth_false(h->flags, x);                         \
            ++h->size; ++h->n_occupied;                                 \
            *ret = 1;                                                   \
        } else if (__ac_isdel(h->flags, x)) {                           \
            h->keys[x] = key;                                           \
            __ac_set_isboth_false(h->flags, x);                         \
            ++h->size;                                                  \
            *ret = 2;                                                   \
        } else *ret = 0;                                                \
        return x;                                                       \
    }                                                                   \
    static inline void kh_del_##name(kh_##name##_t *h, khint_t x)       \
    {                                                                   \
        if (x != h->n_buckets && !__ac_iseither(h->flags, x)) {         \
            __ac_set_isdel_true(h->flags, x);                           \
            --h->size;                                                  \
        }                                                               \
    }

/* --- BEGIN OF HASH FUNCTIONS --- */ //这里是hash函数定义

#define kh_int_hash_func(key) (uint32_t)(key) //32位的hash
#define kh_int_hash_equal(a, b) (a == b)
#define kh_int64_hash_func(key) (uint32_t)((key)>>33^(key)^(key)<<11) //64位的hash,先移位,再位运算
#define kh_int64_hash_equal(a, b) (a == b)
static inline khint_t __ac_X31_hash_string(const char *s) //可能是进行hash操作
{
    khint_t h = *s;
    if (h) for (++s ; *s; ++s) h = (h << 5) - h + *s; //这个应该是hash操作
    return h;  //h表示hash 值
}
#define kh_str_hash_func(key) __ac_X31_hash_string(key)
#define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)

/* --- END OF HASH FUNCTIONS --- */

/* Other necessary macros... */
//指向上面声明的函数
#define khash_t(name) kh_##name##_t
#define kh_init(name) kh_init_##name()
#define kh_destroy(name, h) kh_destroy_##name(h)
#define kh_clear(name, h) kh_clear_##name(h)
#define kh_resize(name, h, s) kh_resize_##name(h, s)
#define kh_put(name, h, k, r) kh_put_##name(h, k, r)
#define kh_get(name, h, k) kh_get_##name(h, k)
#define kh_del(name, h, k) kh_del_##name(h, k)
//一些操作,这里h应该就是hash的结构
#define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))
#define kh_key(h, x) ((h)->keys[x])
#define kh_val(h, x) ((h)->vals[x])
#define kh_value(h, x) ((h)->vals[x])
#define kh_begin(h) (khint_t)(0)
#define kh_end(h) ((h)->n_buckets) //返回hash桶的数量,用于查询
#define kh_size(h) ((h)->size)
#define kh_n_buckets(h) ((h)->n_buckets)

/* More conenient interfaces */
//一些更加方便的接口,一些简单的借口,指向一个统一的复杂接口
//C中通过这些接口的调用,从而初始化上面的宏
#define KHASH_SET_INIT_INT(name)                                        \
    KHASH_INIT(name, uint32_t, char, 0, kh_int_hash_func, kh_int_hash_equal)

#define KHASH_MAP_INIT_INT(name, khval_t)                               \
    KHASH_INIT(name, uint32_t, khval_t, 1, kh_int_hash_func, kh_int_hash_equal)

#define KHASH_SET_INIT_INT64(name)                                      \
    KHASH_INIT(name, uint64_t, char, 0, kh_int64_hash_func, kh_int64_hash_equal)

#define KHASH_MAP_INIT_INT64(name, khval_t)                             \
    KHASH_INIT(name, uint64_t, khval_t, 1, kh_int64_hash_func, kh_int64_hash_equal)

typedef const char *kh_cstr_t; //这个应该是指向字符串的char指针 即 后面又_STR后缀的
#define KHASH_SET_INIT_STR(name)                                        \
    KHASH_INIT(name, kh_cstr_t, char, 0, kh_str_hash_func, kh_str_hash_equal)

#define KHASH_MAP_INIT_STR(name, khval_t)                               \
    KHASH_INIT(name, kh_cstr_t, khval_t, 1, kh_str_hash_func, kh_str_hash_equal)
	//有 _MAP_的  表示kh_is_map为1
#endif /* __AC_KHASH_H */
